Wet oxidation of ordered mesoporous carbon FDU-15 by using (NH4)2S2O8 for fast adsorption of Sr(II): An investigation on surface chemistry and adsorption mechanism

Surface modification of ordered mesoporous carbon ( OMC) by wet oxidation provides an oxygen-enriched platform for complexation of metal ions. Here, we present a comprehensive study on the surface chemistry and textual property of OMC FDU-15 modified by wet oxidation using (NH4)(2)S2O8 as a benign oxidant. And, for the first time, the adsorption behavior and mechanism of wet-oxidized OMC FDU-15 toward Sr(II) in aqueous solutions were investigated. The mesostructural regularity of the OMC FDU-15 was well-reserved under wet oxidation. Compared to OMC CMK-type counterparts prepared via nanocasting, the OMC FDU-15 by soft template method showed much-enhanced structural stability. Due to the introduction of abundant oxygen-containing species, the oxidized OMC FDU-15 exhibited excellent hydrophilicity and dispersibility in aqueous solutions. The adsorption behavior toward Sr(II) was fully investigated, showing a super-fast adsorption kinetics (< 5 min to reach equilibrium) and a Langmuir adsorption isotherm. Moreover, an in-depth X-ray photoelectron spectroscopy analysis through deconvolution of high resolution C1 s and O1s spectra was implemented to identify the chemical species of the surface functional groups, while probing the adsorption mechanism. The results suggested that oxygen donor atoms in C-O single bonds mainly contribute to the adsorption of Sr(II) via formation of metal-ligand complexation. (C) 2015 Elsevier B.V. All rights reserved.